docs: def create(cls, name, datacenter, subnet=None, gateway=None,
                 background=False):
          """Create a new vlan."""
          if not background and not cls.intty():
              background = True
  
          datacenter_id_ = int(Datacenter.usable_id(datacenter))
  
          vlan_params = {
              'name': name,
              'datacenter_id': datacenter_id_,
          }
  
          if subnet:
              vlan_params['subnet'] = subnet
          if gateway:
              vlan_params['gateway'] = gateway
  
          result = cls.call('hosting.vlan.create', vlan_params)
  
          if not background:
              # interactive mode, run a progress bar
              cls.echo('Creating your vlan.')
              cls.display_progress(result)
              cls.echo('Your vlan %s has been created.' % name)
  
          return result